1/*
2 * Copyright (c) 2000-2001,2004 Apple Computer, Inc. All Rights Reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23
24
25//
26// fdsel - select-style file descriptor set management
27//
28#include "fdsel.h"
29
30
31namespace Security {
32namespace UnixPlusPlus {
33
34
35//
36// Throw the bitvectors away on destruction
37//
38FDSet::~FDSet()
39{
40    delete mBits;
41    delete mUseBits;
42}
43
44
45//
46// Given the old and desired new sizes (in fd_mask words), grow
47// the bitvectors. New storage is zero filled. Note that we preserve
48// the mUseBits vector, so this is safe to do during a post-select scan.
49// This function cannot shrink the bitmaps.
50//
51void FDSet::grow(int oldWords, int newWords)
52{
53    assert(oldWords < newWords);
54    grow(mBits, oldWords, newWords);
55    grow(mUseBits, oldWords, newWords);
56}
57
58void FDSet::grow(fd_mask * &bits, int oldWords, int newWords)
59{
60    fd_mask *newBits = new fd_mask[newWords];
61    memcpy(newBits, bits, oldWords * sizeof(fd_mask));
62    memset(newBits + oldWords, 0, (newWords - oldWords) * sizeof(fd_mask));
63    delete [] bits;
64    bits = newBits;
65}
66
67
68//
69// Set or clear a single bit in the map.
70// No check for overflow is perfomed.
71//
72void FDSet::set(int fd, bool on)
73{
74    if (on) {
75        FD_SET(fd, (fd_set *)mBits);
76    } else {
77        FD_CLR(fd, (fd_set *)mBits);
78        FD_CLR(fd, (fd_set *)mUseBits);
79    }
80}
81
82
83//
84// Copy only the first words fd_mask words from mBits to mUseBits
85// and return that for select(2) use.
86//
87fd_set *FDSet::make(int words)
88{
89    //@@@ if empty -> return NULL (but check caller for [] use)
90    memcpy(mUseBits, mBits, words * sizeof(fd_mask));
91    return (fd_set *)mUseBits;
92}
93
94
95}	// end namespace IPPlusPlus
96}	// end namespace Security
97